Courtship Whistling (Mexico,Kickapoo tribe)
While boys are usually taught that whistling at members of the opposite sex is bad manners, the Kickapoo tribe of Mexico have used it for decades to whisper sweet nothings to their lovers. The practice itself is relatively young (lovers used to communicate with a flute up until 1915). The whistling usually takes place inside the village, during dusk, and is a way for a couple to plan their meet-up for the evening.
To prevent any mix-ups, couples have their own unique tones that they can easily recognize. As anyone in the village can hear it, the couple must also code their whistles carefully to make sure that only they can understand the message. While the whistling itself is usually just a short message, full-length conversations can also take place between the couple. The practice itself isn’t in danger of dying out soon—the boy will often bring a younger brother along , so that he too can learn the art of whistling.